The vast majority of models of treatment of outcome for adolescent alcohol abuse/dependence have been formulated without consideration of important developmental or psychiatric factors which clearly relapse and recovery. The present proposal seeks 5 years of funding to address 2 developmentally relevant questions: 1) How does psychiatric co-morbidity influence adolescent treatment outcome? and 2) What are the young adult outcomes of those who received treatment for alcohol abuse during their adolescence? Building on a well established program of developmentally focused adolescent alcohol treatment outcome research, this competitive renewal seeks to first follow to age 30, 250 individuals with a history of adolescent alcohol treatment whom we have assessed biannually for 8 years. Assessment through this highest risk period for the development of alcohol dependence will provide information on alcohol/drug, mental health and physical health outcomes, neurocognitive status, as well as functioning in major life domains. The present proposal would also expand a sample of alcohol abusing adolescents with concomitant DSM-IV psychiatric disorders who were initially assessed during treatment and followed for one year. It is proposed that the adolescent sample be expanded to 300 (as originally approved) and followed until two years post treatment to evaluate changes in psychiatric symptoms/disorders in relation to alcohol/drug involvement as these individuals transition through late adolescence. Using well established theoretically derived protocols, the present studies seek to expand models of clinical course of alcohol abuse (relapse and recovery) to include developmental transitions and psychiatric co-morbidity. Gender, ethnic and diagnostic group differences in clinical course will also be evaluated.